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Monster Freight

Engines MONSTER freight-engines, almost

twice as large and three times as strong as the ordinary type, are being installed on the Baltimore & Ohio Southwestern Railroad. This photograph shows one of these powerful freightpullers just as it was run out of Chillicothe, where it was built, to Cincinnati on its trial trip. Thirty of these monsters will soon be in use over the entire system. In order that these extra heavy engines can pass successfully over the entire road, it will be necessary to strengthen bridges and roadbeds in various places.

While the new engines resemble the old style of freight-handlers in appearance, many improvements have been installed upon the new type. The immense boiler sits twice as high as in the ordinary engine, in order to afford room. for the extra large fire-box and the extra mechanism not to be found upon the little freight-handlers.

The Dufaux Airship EXCESSIVE weight in the motor has been a difficulty that has long troubled would-be creators of a successful airship. Now, however, two Swiss engineers, MM. Henri and Armand Dufaux, have succeeded in combining sufficient power with remarkable light

ness-diminishing the weight to less than 3.3 pounds per horse-power, and constructing a benzine motor of a little over 2-horse-power capacity, which, including all accessories, weighs only 9.9 pounds.

This motor drives four horizontal screws placed in pairs on both sides of the motor at the ends of a steel-tube frame. These screws are of uniform construction, consisting of two sections of 6 feet 6.7 inches diameter. The screws belonging to the same pair, mounted one above the other, rotate in the same direction, while the two pairs turn in opposite directions. The screws are mounted loosely on the shaft, and are driven by means of a wooden lever fitted on the latter, which is connected to the screws by four caoutchouc springs, thus avoiding any risk of damage to any delicate parts in case of a too sudden rise. The weight of each screw is only 15.9 ounces.

The arms are covered with varnished silk, and consist of thin deal boards, three of which are glued together.

The motor has two double-acting cylinders placed one above another and fitted with four separate ignition devices. The gasefier, being of aluminum and copper, has very little weight, the level being maintained constant by a special construction. The igniting current is supplied by accumulators, and distributed by a Dufaux coil. The primary current is intermittent, while the secondary is maintained constant in order to avoid excessive tensions.

Experiments were recently made on the grounds of the Paris Aero-Club, after tests on a large scale had been carried out

in the inventors' native town. In the Paris experiments, the apparatus was enabled to rise of its own accord, while being guided by a wire rope running over pulleys. After the motor had been started and the screws thrown in, the whole apparatus would fly up readily, in excellent equilibrium, maintaining itself permanently in the same vertical plane and being even capable of supporting an overweight up to 13.2 pounds. When loaded with 14.3 pounds, it was found to keep itself soaring in the air without either dropping or rising. Considering that the machine weighs only 37.5 pounds, this result may be called excellent.

Telegraphing a Portrait

PROF. ARTHUR KORN, of Munich,

Bavaria, has devised a practicable method for the electrical transmission of photographs as distinguished from the mere handwriting and line sketches which can be sent by the telautograph. The first practical results were secured in 1904; but later improvements, recently described before the Berlin Electrical Society, have enabled him to transmit photographs with remarkable definition over lines offering a resistance of fully 12,000 ohms-the equivalent of a distance of several thousands of miles, the time of transmission being 10 to 20 minutes, and the size of the pictures 5 by 7 inches.

The transparent film containing the

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A-Portrait of Prof. Korn transmitted telegraphically in 20 minutes, through a line of 12,000 ohms' resistance, corresponding to several thousands of miles' distance. B-Telegraphed portrait of the Prince Regent of Bavaria.

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receiving film, thus gradually reproducing the original picture.

The luminosity of the exhausted tube at the receiving station is graduated by means of Tesla currents. The tube is enveloped with black paper and sealingwax, and has only an exceedingly small aperture through which the radiation of the tube is allowed to strike the receiving film. The high-tension Tesla currents are led to the tube from the Tesla coil over the spark distances F,F, and FF, (Fig. 2), which, by means of an index moved by a galvanometer w, are increased or reduced according to the greater or less intensity of the currents coming from the transmitting station, i. e., to the greater or less brightness of the corresponding elements u of the transmitting film. Now, according to the distances FF2 and F3F4, the tube will give out a stronger or weaker flashing, thus more or less affecting the photographic film at the receiving station.

In the latest type of apparatus the spark distances are replaced by suitable rheostats inserting a resistance that depends on the position of the galvanometer needle.

For the transmission of handwriting, sketches, diagrams, etc., 'the film at the

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ever the point of the pencil is in contact with the non-conductive portion of the metal foil. The currents of intermittent intensity thus produced in the long-distance line, will reproduce at the receiving station the original handwriting at the rate of 500 to 600 words per hour.

Professor Korn believes that his apparatus will allow of a tele-vision after the time of transmission of the photographs has been further reduced.

In principle tele-vision is, it is true, possible even now, provided a very high number of conductors be used, complicating in proportion the transmitting and receiving apparatus. Owing, however, to the prohibitory cost, this process of tele-vision is at present quite impracticable, while there are no theoretical reasons in the way of a future realization of this dream of so many inventors.--DR. ALFRED GRADENWITZ.

The Teredo

ONE of the greatest enemies in the

world to wood is the insect known as the Teredo navalis. It is really an

animated auger, for it will bore through the hardest species of trees unless they are protected from its pointed head. For this reason it is impossible to support wharves in water frequented by the teredo, for it will practically destroy a pile in the course of two or three yearsno matter how large may be the column of wood-unless it is protected by being soaked in creosote or some similar substance. Creosote is a product of distillation of coal-tar. It is an oily fluid, having wonderful antiseptic and preservative properties. In the treatment of wood, it is forced into the tissues under pressure in air-tight chambers.

The teredo is a native of tropical climates, but as far north as Puget Sound its destruction is apparent. The accompanying photograph shows two pieces of Washington cedar. These originally formed a ship's timbers, and were washed upon the shores of the Sound after a wreck. The sides shown in the photograph were on the inside of the hull, consequently were not exposed to the attacks of the insect until after the vessel went to pieces. As will be noted, the smaller strip is so honeycombed that it actually contains more holes than wood, while the larger is perforated through and through. A close examina

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Safety Valves on Huckleberry Pies TO THE EDITOR: I hasten to inform you of the following interesting and important development in engineering practice:

An awful accident occurred on January 25 last, in which a number of guests at an East Side boarding house in Paterson, N. J., were more or less seriously injured.

The cook, it appears, had constructed a

huckleberry pie of large dimensions, but had, unfortunately, neglected to follow the landlady's specification in the matter of making blow holes in the upper crust. The result was that when the pie was brought on the table and a knife inserted, the whole pie exploded, covering almost everybody at the table with confusion and boiling hot blueberries.

With a view of preventing further catastrophes of this kind a bill has been introduced in the New Jersey legislature, providing for the appointment of a State Pie Inspector and further providing that no huckleberry pies shall be served within the limits of the State which have not successfully withstood a hydrostatic test of ten pounds to the square inch. A third provision is that each pie shall be supplied with a steam gauge and safety valve, as shown in the illustration.-J. O'SULLIVAN ADDICKS.

Word by Wire

A CLERGYMAN, having occasion to go to London before Christmas, was asked by his wife

to buy a text for the gallery of the church for the Christmas decorations.

He was very busy, and forgot all about it till just before leaving, so wired for instructions to his wife as to the words and dimensions. She wired back the following message: "Unto us a son is born, nine feet long by three feet high."

Bill Collecting by Electricity

TO THE EDITOR: Do you think the following action was in violation of the ethics of the engineering profession?

I have been engaged in thawing out water pipes by electricity and have fixed a regular charge of $10 a job. The other day I was just getting through, when an old German, who lived next to the house in which I was working, came over and asked me to thaw out his pipes, too.

Everything was ready and it only took about ten minutes to do the job. When I got through and presented to him my bill for $10, he threw up both hands and refused to pay it.

"Do I understand that you absolutely refuse to pay this bill?" I asked, finally, after a long argument.

"I never pay in the world!" the old man de clared with an oath.

"Then, George," I said, turning to my fore

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